Heavy-duty aerosol cleaner

ABSTRACT

A HEAVY-DUTY FOAMING AEROSOL ABRASIVE CLEANER COMPOSITION PARTICULARLY ADAPTED FOR CLEANING HARD SURFACE FLOORS WITHOUT DETRIMENTLA EFFECT ON FLOORS OR FLOOR FINISHES. THE CLEANER COMPRISES A THIXOTROPIC SUSPENSION OF BENTONITE, ABRASIVE PARTICLES, REDUCING AGENT FOR CORROSION PREVENTION AN EFFECTIVE AMOUNT OF AT LEAST ONE HIGHER FATTY ACID ALKANOLAMIDE TO PROVIDE A VISABLE FOAM, AND SUFFICIENT WATER TO PROVIDE THE DESIRED VISCOSTIY.

3,650,956 HEAVY-DUTY AEROSOL CLEANER David L. Strand, Maplewood, andRoger L. Abler, White Bear Lake, Minn., assignors to Minnesota Miningand Manufacturing Company, St. Paul, Minn. No Drawing. Filed May 28,1969, Ser. No. 828,701 Int. Cl. (111d 17/00 US. Cl. 252-90 5 ClaimsABSTRACT OF THE DISCLOSURE A heavy-duty foaming aerosol abrasive cleanercomposition particularly adapted for cleaning hard surface floorswithout detrimental effect on floors or fioor finishes. The cleanercomprises a thixotropic suspension of bentonite, abrasive particles,reducing agent for corrosion prevention, an effective amount of at leastone higher fatty acid alkanolamide to provide a visible foam, andsufficient water to provide the desired viscosity.

BACKGROUND OF THE INVENTION This invention relates to heavy-duty foamingaerosol abrasive cleaner compositions particularly adapted for use withrotary floor cleaning machines to clean hard surface floors.

The floor cleaning art has desired cleaner compositions to quickly anduniformly clean a floor down to the base polish coat, without the use ofcopious amounts of water, without removing the floor from service andwith a minimum amount of labor. Soil such as black marks and imbeddeddirt has typically been removed by applying copious amounts of aqueousdetergent or soap solutions and scrubbing the floor with low-densityabrasive cleaning pads, steel wool pads, or bristle brushes driven byconventional floor cleaning and polishing machines. The detergent orsoap solution is then removed, disposed of, and the floor surface rinsedwith water. This traditional method is slow, cumbersome, laborious,expensive, removes the floor from safe service and often removes thebase polish coat, necessitating subsequent reapplication. Additionally,aqueous solutions darken, swell, and rot wood floors. Further, the floorcleaning machine often throws detergent and soil on walls and furniturenecessitating expenditure of extra labor for cleanup.

Liquid detergent compositions and abrasive cleaner com-positionsdispensable by means of plastic squeeze bottle or aerosol spray areknown in the art, typical compositions being shown in US. Pats.2,920,045; 3,149,078; 3,210,285; and 3,210,286; and the R. T. VanderbiltCompany Trade Bulletin No. 44 (1964) on page 27. Cleaner compositions ofthis type have been found unsatisfactory for use with floor cleaningmachines as a replacement for traditional floor cleaning methods. Thesecompositions either provide a thick paste or a stiff, thick,slowdraining, persistent foam similar to shaving cream or whipped cream.A stiff, thick paste or foam neither wets the floor surface nor flowsunder the floor pad, but is pushed along the floor surface or thrown tothe side onto walls, furniture, etc. Other difficulties encountered withprior art aerosol abrasive cleaners include settling and separation ofthe composition Within the container and plugging of the spray nozzleorifice.

Thus, despite the desirability of a cleaner to replace the slow,cumbersome, laborious, expensive, unsafe use of aqueous detergent andsoap solutions, a truly satisfactory product has never heretoforeexisted.

nited States Patent C 3,650,056 Patented Mar. 21, 1972 SUMMARY Thisinvention provides a cleaner composition having excellent soil removingproperties. The cleaner effectively replaces the slow, cumbersome,laborious, expensive, unsafe use of aqueous detergent and soapsolutions. The composition provides an aerosol-dispensable foam which isreadily visible on the floor and will persist for several minutes, butwhich breaks to a liquid when subjected to mechanical agitation such asthat applied by a floor cleaning machine. The foaming composition isaerosoldispensable without plugging of the spray nozzle orifice andwithout settling or separation of the composition. The foam cleaner,while particularly adapted for use on floors with rotary cleaningmachines, can also be used to clean such articles as vinyl upholstery,sinks, dishes, pots, and pans.

In accordance with the invention, the heavy-duty abrasive cleanercomposition comprises a homogeneous dispersion of bentonite,water-insoluble abrasive particles having a particle size below 325mesh, an effective amount of compatible reducing agent to preventcontainer corrosion, an effective amount of at least one higher fattyacid alkanolamide, and sufiicient water to provide an apparentBrookfield solution viscosity of about 200 to about 800 centipoises whenmeasured with a No. 2 spindle at 6 r.p.m. If desired, minor amounts ofother components may be included for specific formulation purposes suchas antibacterial aids and odorants.

It has been found that the cleaner composition of this invention, havingan apparent solution viscosity of about 200 to about 800 centipoises, isreadily dispensable from a conventional aerosol container to provide adesired foam which is readily visible for several minutes when sprayedon a floor surface, but which will break to a liquid when subjected tomechanical shear force. A 1- second spray of this cleaner compositionfrom a distance of about 12 inches provides a thin foam generally lessthan about inch thick which persists for about 2 to about 5 minutes.This length of time permits the floor machine operator to see where hehas applied cleaner, the foam breaking to a liquid when contacted by thefloor machine. The ability of the foam to break to a liquid whensubjected to shear force is readily demonstrated by applying a l-secondspray to the palm of ones hand and thereafter rubbing the hands togetherseveral times. The foam quickly breaks to a liquid, in sharp contrast toa shaving cream foam which persists for long periods of time, even undershear force.

The aerosol package used with the heavy-duty abrasive cleanercompositions of this invention generally comprises a pressure-tightcontainer having a typical aerosol dispensing valve which controls flowthrough a discharge conduit leading from the base of the container. Apreferred container utilizes a dispensing valve having a vapor phasehole therein. This valve also permits the cleaner composition to bedispensed when the container is in either an upright or invertedposition. The propellant utilized with aerosol cleaner compositions mustnot react with the cleaner components to render them ineffective orcause the propellant to hydrolyze or otherwise decompose and lose itseffectiveness. The propellant, which is employed in the amount of fromabout 5 to about 20% by weight of the contents of the container,preferably from about 6 to about 12%, is propane, butane, isobutane, ormixtures thereof, with isobutane being preferred because of its idealvapor pressure at ambient temperatures.

Bentonite is a substantially water-insoluble clay which displays strongcolloidal properties and increases its volume several fold by swelling,when in contact with water,

giving rise to a thixotropic, gelatinous suspension capable of holdingsubstantial amounts of abrasive particles in suspension. The solutionviscosity obtained is dependent on the particular bentonite utilized andthe amount of shear force used in preparing the suspension. It has beenfound that Wyoming bentonite which has a particle size of 4 microns orsmaller, with particles smaller than 2 microns predominating, andcontaining at least 85% montmorillonite, provides particularlysatisfactory foams. Montmorillonite, is a high aluminum content silicatehaving a plate like crystal structure. Since the solution viscosity ofeach lot of bentonite will vary slightly, it has been found best to usean amount of bentonite and a degree of shear mixing which provides aBrookfield viscosity of about 400 to about 600 centipoises when 100parts by weight of bentonite is mixed with 2000 parts by weight of waterand measured at r.p.m. with a No. 2 spindle.

The abrasive particles, which substantially increase the heavy-dutycleaning properties of the composition, may be selected from a largegroup of well known materials in H cluding synthetic alumina, emery,corundum, silicon carbide, volcanic ash, iron oxide, diatomaceous earth,boron carbide, pumice, feldspar, and mixtures thereof; however, it ispreferred to employ silica as the abrasive in the present compositionsbecause of its highly eifective cleaning action. The particle size ofthe abrasive must be such that the abrasive will readily remainsuspended in the composition and pass through the nozzle orifice of anaerosol container. Abrasive particles of a size such that they passthrough a 325 mesh U.S. Standard sieve may be utilized. It has beenfound that an effective amount of abrasive particles which readilyremain suspended in 100 parts of bentonite ranges from about 100 toabout 500 parts by weight, preferably about 200 parts. Use of less thanabout 100 parts by weight of abrasive per 100 parts of bentonite doesnot provide effective abrading and cleaning action, while use of morethan about 500 parts provides a suspension which has an excessively highviscosity and cannot be readily dispensed from aerosol containers, issubject to settling and separation, or both.

About 650 to 750 parts of water blended with 100 parts ofbentonite-abrasive mixture provides a suspension viscosity of about 400cps. when tested with a Brookfield No. 2 spindle at 6 r.p.m. This amountof water is about 1500 to about 3000 parts by weight per 100 parts ofbentonite. Use of less Water provides an excessively viscous dispersionwhich is not readily dispensable from the aerosol container, while useof more water provides a low viscosity dispersion which is not stableand settles or separates. The amount of water necessary to provide thedesired viscosity will vary somewhat with each particular lot ofbentonite used. In preparing the composition, the water is mixed withthe bentonite using shear agitation, to provide a stable thixotropicsuspension and the abrasive thereafter blended in.

If desired a portion of the water in the suspension can be replaced withother liquid components. For example, the inclusion of up to about 150parts by weight per 100 parts of bentonite, of lower aliphatic alcoholssuch as methanol, ethanol, propanol, isopropanol, etc., isopropanolbeing preferred, aids in increasing the cleaning eifectiveness of thecomposition. It is also thought that the alcohol causes the aerosolpropellant to become somewhat soluble in the composition, therebyproviding a more homogeneous foam. Greater amounts of alcohol may beadded if desired but have not been found to be of beneficial value.

The heavy-duty aerosol cleaner composition of this invention essentiallycontains an effective amount of at least one compatible corrosionpreventing agent. It has been found that aerosol container linings arenot sufficiently continuous to prevent aqueous solutions frompenetrating the coating and attacking the can metal. Compatible reducingagents such as sodium nitrite, sodium benzoate, sodium borate, phosphateesters, morpholine, and water soluble organic amines have been foundparticularly effective. Compatible reducing agents are those whicheither dissolve or disperse in the composition to provide a homogeneousdispersion. Amounts of reducing agent effective to prevent corrosionhave been found to range from less than about 1 part to about 25 partsby weight per 100 parts of bentonite, about 1 to about 15 beingpreferred.

The aerosol cleaner composition of this invention also essentiallycontains an effective amount of at least one higher fatty acidalkanolamide, such as the monoethanol amides, diethanol amides, orisopropanol amides wherein the acyl radical has about 10 to about 18carbon atoms. Examples of such amides are lauric, capric, caprylic,palmitic, stean'c, oleic, linoleic, and myristic diethanol amide,monoethanol amide, and isopropanol amide. These alkanol amides provide areadily visible foam such that a floor cleaning machine operator can seewhere he has dispensed cleaner, the foam being clear and not visiblewithout alkanolamide. Further, these alkanolamides cause the foam to wetthe floor surface, persist for only a few minutes, and break easily. Aneffective amount of alkanolamide to provide a readily visible foam hasbeen found to be about 5 to about 100 parts by weight per 100 parts ofbentonite, about 10 to about 60 parts being preferred. Using less thanabout 3 parts by weight per 100 parts of bentonite does not provide asufficiently visible foam, while more than about 100 parts provides anexcessively stiff and therefore undesirable foam. Further, use ofexcessive alkanolamide leaves a residue on the floor surface.

If desired, ammonium hydroxide may be included in the composition toprovide numerous beneficial properties. For example, it functions as apreservative by providing a pH greater than 9, a corrosion inhibitor, aviscosity stabilizer, and an aid in cleaning the floor surface. Theammonium hydroxide, being fugitive and volatile, evaporates rapidly fromthe floor surface and does harm the floor coating nor increase its watersensitivity by virtue of residual caustic. Effective amounts ofconcentrated (28%) ammonium hydroxide have been found to range up toabout 250 parts by weight per 100 parts of bentonite, 30 parts beingpreferred. Minor amounts of other components such as odorants andcoloring agents may be added if desired.

The following examples, in which all parts are by weight unlessotherwise noted, illustrate preparation of the heavy-duty aerosolabrasive cleaner composition of this invention, without limiting thescope thereof.

DESCRIPTION OF PREFERRED EMBODIMENTS Example I Forty gms. of bentonitehaving a 90% montmorillonite content, a specific gravity of 2.7, anindex of refraction of 1.55, and a particle size such that 96% passesthrough a 200 mesh U.S. Standard sieve (available from the AmericanColloid Company) was blended into 823.9 gms. of water and mixed withshear agitation by means of an air driven laboratory propeller mixeruntil a viscosity of 500 cps. was obtained. This took about one hour.Then gms. of grade 360 and finer ground silica (Nicrosil, Ottowa SilicaCo.), 21.3 gms. isopropyl alcohol, 21.3 gms. concentrated (28%) ammoniumhydroxide, and 8.5 gms. of a coconut fatty acid diethanol amide (HyonicLA- 45, Nopco Chemical Company) were blended into the mixture to providea thixotropic suspension having a pH of about 10.7. The Brookfieldviscosity was 800 cps., when tested using a No. 2 spindle at 6 r.p.m.

Six hundred grams of the suspension was filtered through a 60 meshscreen and packaged in a 24-ounce lined aerosol can together with 60grams of isobutane propellant. A valve having a 0.025 inch meteringorifice and a 0.020 inch vapor phase hole (Aerosol Research KN38 valve)was crimped onto the container. The spray tip had a.

0.025 inch diameter orifice (Aerosol Research Company, RKN-105) and thedelivery rate of the product was found to be 1.9 gms. per second.

The effectiveness of this cleaner composition was evaluated byinstalling a low-density fibrous abrasive floor cleaning pad(Scotch-'Brite Brand Blue Cleaner Pad, Minnesota Mining andManufacturing Company) on a 17-inch commercial rotary floor machine andcleaning a vinyl asbestos tile floor coated with a self-polishingacrylic floor polish (Step Ahead," S. C. Johnson Co.) and heavily soiledwith black shoe and crayon marks, and embedded dirt. This floor area wassprayed with the aerosol cleaner composition to provide a low butreadily visible foam on the floor surface and the floor cleaning machinewith the low-density abrasive pad attached thereto was passed over thefoam 6 times. It was found that the embedded dirt, shoe marks, andcrayon marks were removed from the floor surface, there was no depositof residue on the floor surface that could not be removed by drymopping, and the water sensitivity of the remaining floor coating wasnot increased.

A control test was performed by flooding a similarly soiled floorsurface with water containing a commercial floor cleaning detergent, andscrubbing the floor with the same low-density abrasive floor pad andfloor polishing machine. After 6 passes over the soiled floor area,removal of the detergent solution, and rinsing, the floor surface, whileclean, was essentially void of polish. The control test was found totake about 3 times as long to clean the same area floor.

Example II Another cleaner composition containing a greater amount ofabrasive was prepared using the same components and the same procedureutilized in Example I. The formulation was as follows:

This composition was packaged and tested as described in Example I andwas found to effectively remove imbedded soil from hard surface floors.This composition was also used to clean a badly stained brush-finishstainless steel sink. All stains were readily removed with a minimumamount of scrubbing with a low-density abrasive pad.

What we claim is:

1. An aerosol-dispensible foam cleaner composition consistingessentially of about 100 parts by weight of bentonite clay, about 100 toabout 500 parts by weight of water-insoluble abrasive particles having aparticle size such that they pass through a 325 mesh sieve, 100 parts byweight of at least one higher fatty acid alkanolamide to provide avisible foam, said alkanolamide selected from the group consisting ofmonoethanol amides, diethanol amides, or isopropanol amides wherein theacyl radical has about 10 to about 18 carbon atoms, about 1 to about 25parts by weight of corrosion inhibitor, up to about 150 parts of atleast one lower aliphatic alcohol, about 10 to about 250 parts ofconcentrated ammonium hydroxide, and about 1500 to about 3000 parts byweight of water, said composition having an apparent Brookfield solutionviscosity of about 200 to about 800 centipoises when measured on a No. 2spindle at 6 r.p.m.

2. The composition of claim 1 wherein the alcohol is isopropanol.

3. The composition of claim 1 wherein the alkanol amide is a coconutfatty acid diethanol amide.

4. An aerosol-dispensable foam cleaner composition consistingessentially of about 100 parts by weight of bentonite clay containing atleast high aluminum content montmorillonite, about to about 500 parts byweight of water-insoluble silica abrasive particles having a particlesize such that they pass through a 325 mesh sieve, about 1 to about 25parts by weight of corrosion inhibitor, about 5 to about 100 parts byweight of a coconut fatty acid diethanol amide, about 10 to about 250parts by weight of concentrated ammonium hydroxide, up to about 150parts of at least one lower aliphatic alcohol and about 1500 to about3000 parts by weight of water, said composition having an apparentBrookfield solution viscosity of about 200 to about 800 centipoises,when measured with a No. 2 spindle at 6 r.p.m.

5. An aerosol-dispensable foam cleaner composition consistingessentially of about 100 parts by weight of bentonite clay containing atleast 85% high aluminum content montmorillonite, about 100 to about 500parts by weight of silica particles having a particle size such thatthey pass through a 325 mesh sieve, about 1 to about 25 parts of sodiumnitrite, about 1 to about 150 parts by weight of isopropanol, about 10to about 250 parts by weight of concentrated ammonium hydroxide, about 5to about 100 parts by weight of at least one coconut fatty aciddiethanol amide, and about 1500 to about 3000 parts by weight of water,said composition having an apparent Brookfield solution viscosity ofabout 200 to about 800 centipoises when measured with a No. 2 spindle at6 r.p.m.

References Cited UNITED STATES PATENTS 2,489,848 11/1949 Bacon et a1.252 2,524,380 10/1950 Flaxman 252139 2,920,045 1/ 1960 Hearn et a1.252-137 3,149,078 9/1964 Zmoda 252-137 3,210,285 10/1965 Gangwisch252-137 3,210,286 10/1965 Gangwisch 252137 LEON D. ROSDOL, PrimaryExaminer W. E. SCHULZ, Assistant Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Inventor) David L.Strand and Roger L. Abler It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column A, line 37, and does harm" should be "and does not harm" Signedand sealed this 11 th day of July 1972.

(SEAL) Attest:

EDWARD M.FLETCI IER, JR. ROBERT GOTTSCHALK A-ttesting OfficerCommissioner of Patents FORM Po-1050 (10-69) USCOMM'DC 50376-P69 9 05.GOVERNMENT PRINTING OFFICE i969 0-386-334

